Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
  • A61F9/00—Methods or devices for treatment of the eyes; Devices for putting-in contact lenses; Devices to correct squinting; Apparatus to guide the blind; Protective devices for the eyes, carried on the body or in the hand
  • A61F9/007—Methods or devices for eye surgery
  • A61F9/00781—Apparatus for modifying intraocular pressure, e.g. for glaucoma treatment

Definitions

• the invention relates to an implant intended to be placed in the sclera of the eye after a sclerotomy operation with or without trabeculectomy.
• Glaucoma is currently treated in the most serious cases by a surgical procedure called trabeculectomy.
• This intervention consists, after conjunctival disinsertion, in making a trap door in the sclera by cutting out a sawdust flap (cleavage of the planes of the sclera up to the trabecular meshwork) and incising the trabecular meshwork to allow a flow of aqueous humor contained in the chamber anterior, which decreases intraocular tension and limits the pathological consequences of glaucoma.
• Another type of intervention is currently practiced to treat glaucoma: it consists in putting in place a valve associated with a conduit which opens into the anterior chamber to allow a flow of aqueous humor in the event of an increase in pressure in this chamber .
• this technique has drawbacks: firstly, it requires a complex operation affecting the anterior chamber, with a deleterious risk on the corneal endothelium (surgeons used to trabeculectomies are often reluctant to perform this type of complex surgical intervention and risky).
• the conduit tends to become blocked so that the effectiveness of the device, which is good after installation, decreases rapidly over time.
• the duct is sometimes expelled from the anterior chamber. It should be noted that these valves have a relatively complex structure which makes them expensive to manufacture.
• US Patent 4,521,210 describes an elongated implant which is disposed above the choroid at the interface of the latter and of the sclera.
• This implant has a tapered portion which enters the anterior chamber. It has the same drawbacks as the previous one, even if its great length and the holes and passages provided therein ensure better evacuation of the aqueous humor. In addition, its implementation seems extremely delicate given the dimensions of this implant and its position at the choroid / sclera interface.
• the present invention proposes to provide a new implant remedying the aforementioned defects and having a long-lasting effect in the therapy of glaucoma.
• a first objective of the invention is to provide an implant allowing satisfactory flow of the aqueous humor from the anterior chamber, continuous flow subject to reduced risks of obturation over time.
• Another objective is to provide an implant capable of being placed either by a simple sclerotomy operation during which the trabecular meshwork is not affected, or by a trabeculectomy intervention not affecting the anterior chamber of the eye and corneal endothelium (this implant which does not necessarily require a trabeculectomy will be designated by "sclerotomy implant").
• the sclerotomy implant targeted by the present invention is in the form of a wafer made of a biocompatible material and is characterized in that it comprises:
• trabecular end a first end, called the trabecular end, adapted to be placed against the trabecular meshwork, which can be left intact or undergo a trabeculectomy as in traditional techniques
• trabecular end a first part, called intra-scleral, carrying the trabecular end and adapted for be able to be inserted into the hatch under the sawn shutter
• sub- conjunctival extending the intra-scleral part and adapted to exit the sclera and lodge under the conjunctiva in contact with it
• - stop means located at the junction of the intra-scleral part and the subconjunctival part and adapted to be able to block said intra-scleral part in the flap
• - continuous flow means extending along the intra-scleral part and subconjunctival part between the trabecular end and the external end in order to allow a flow of the aqueous humor from the trabecular meshwork to the conjunctiva, either by filtration through the trabecular meshwork if it is left intact, or by the incision made in the case of trabeculectomy.
• these continuous flow means comprise at least one continuous groove formed along the intra-scleral part and the subconjunctival part so as to open out at the trabecular end and external end.
• the implant can also be made of a porous material, the continuous flow means being constituted by internal passages originating from the porosity of the material.
• the two types of flow means are combined: the implant material is porous and the flow means comprise, on the one hand, at least one continuous groove formed along the intra parts -scleral and subconjunctival part, on the other hand, internal passages coming from the porosity of the material.
• the trabecular end has a concave shape with a radius of curvature substantially between 4 mm and 8 mm. This end thus fits the shape of the trabecular meshwork in contact with which it is placed, which promotes the collection of aqueous humor and its evacuation through the means of flow of the implant (in particular in the absence of trabeculectomy, in the case where the trabecular meshwork is left intact).
• the stop means located at the junction of the intra-scleral part and the subconjunctival part preferably comprise shoulders, arranged on either side of the intra-scleral part and defined by a width of said intra part -scleral larger than that of the subconjunctival part. As will be seen below, these shoulders come to cooperate with the stitches which are practiced at the end of the intervention to maintain the sawdust flap in the flap above the implant: the intra-scleral part is thus locked in a stable position between the trabecular meshwork and these stitches.
• the subconjunctival part which extends said intra-scleral part is arranged under the conjunctiva in contact with the latter and allows the aqueous humor circulating in the means of flow of the implant to leave the sclera to pour under the conjunctiva without risk of blockage.
• FIG. 1 - Figures 1, 2, 3 and 4 represent - on a very dilated scale (scale 10 approximately) - an implant respectively in perspective, in front view along Vi, in section AA 'and in bottom view according to V2, - Figures 5 , 6, 7 and 8 schematically illustrate the placement of said implant during a trabeculectomy,
• FIG. 9 shows in perspective a implant variant
• FIGS. 1 to 4 illustrates this implant placed after a simple sclerotomy operation not affecting the trabecular meshwork.
• the implant shown by way of example in FIGS. 1 to 4 is in the form of a thin elongated wafer made of a biocompatible material, in particular of methylmetacrylate / vinylpyrolidone copolymer. The relative proportions of the two compounds are in particular around 48% and 52%.
• Such a copolymer has a high porosity which can be measured by its hydrophilicity rate of the order of 40% (mass of water capable of being absorbed relative to the mass of dry copolymer).
• the dimensions provided below without limitation correspond to the hydrated implant and decreases by about 20% when the implant is dry.
• the implant essentially comprises two parts in the general shape of a rectangular parallelepiped: an intra-scleral part 1 and a subconjunctival part 5 narrower than the first.
• the intra-scleral part is provided with a trabecular end 2, in the example of planar shape, which is called to come to be placed opposite the trabecular meshwork and whose dimensions are greater than those of the incision (which in this example will be practiced in this one) so as to be stopped by the trabecular meshwork.
• This end will in practice have a width -c- substantially between 2 mm and 4 mm, in the example equal to 3 mm (to within ⁇ 20%) so as to protrude on either side of the trabecular meshwork incision. (whose length is always less than 2 mm).
• the intra-scleral part 1 has a so-called upper face 3 and a so-called lower face 4 of substantially square shape with side -c- equal to 3 mm (to within ⁇ 20%).
• of said intra-scleral part is in particular 0.50 mm (to within ⁇ 20%).
• the subconjunctival part 5 which extends the intra-scleral part described above ends with a so-called external end 6 and has dimensions smaller than those of the intra-scleral part.
• the junction between the two parts defines two shoulders 7a, 7b located on either side of the intra-scleral part; these shoulders are called upon to act as stopping means ensuring blockage of the implant during the execution of the stitches at the end of the intervention.
• the subconjunctival part 5 has an upper face 8 and a lower face 9 of rectangular shape, having one side r-
• the subconjunctival part has a thickness - & 2 ⁇ 9 u i es t in particular equal to 0.25 mm (to within ⁇ 20%) (of the order of half the thickness -e-
• the intra-scleral and subconjunctival parts have, in the example shown, lower faces 3 and 8 located substantially in the same plane and opposite upper faces 4 and 9 which are offset so that the upper face of the subconjunctival part 5 is set back relative to that of the intra-scleral part 1. Furthermore, a continuous groove 10 is formed along the implant in the interscleral 1 and subconjunctival parts 5 so as to open, on either side of the implant, at the trabecular end 2 and external end 6.
• This groove is in the example arranged along the axis of the implant and has a section whose bottom is in the form of a circular section or in an open angle; in the intra-scleral part 1, it opens on the upper face 4 by a portion with parallel faces 10a, while it opens on the upper face 9 of the subconjunctival part by divergent faces 10b.
• the plate described above is used as a sclerotomy implant (with or without trabeculectomy) to treat glaucoma of the eye through implantation in the eye such as:
• the trabecular end 2 is placed against the trabecular meshwork and stopped by the latter without penetration into the anterior chamber, the subconjunctival part 5 is disposed under the conjunctiva in contact with the latter,
• the stop means 7a, 7b cooperate with stitches S- ⁇ , ⁇ > 2 to block the subconjunctival part 1 in the trap door T.
• FIGs 5 to 8 illustrate the placement in one eye in the case where a trabeculectomy is performed.
• the implant is previously impregnated with an aqueous solution until saturation.
• a sawdust flap V ⁇ _ is cut from the sclera so as to form a trap door T.
• the trabecular meshwork is then incised.
• Figure 6 shows this incision in I c .
• the implant P is presented as shown in this figure with its trabecular end 2 on the side of the trabecular meshwork and its external end 6 on the side of the conjunctiva; the upper face 3, 8 is arranged above and the lower face 4, 9 which is provided with the groove 10 is located opposite the fabrics.
• the implant is inserted into the eye so that its intra-scleral part 1 comes to lodge in the trap door T with its trabecular end 2 against the trabecular meshwork facing the incision I c , and that its subconjunctival part 5 comes to bear against the conjunctiva outside the hatch; in this position, the outer end 6 is located outside the sclera against the conjunctiva.
• the sawdust flap V ⁇ _ is then folded back towards the hatch and stitches S-], S2 are made in the hollow of the shoulders 7a and 7b of the implant to fix the flap on the sclera.
• the intra-scleral part of the implant is then blocked in the trapdoor between the trabecular meshwork and these stitches.
• the conjunctiva can then be brought to cover the whole in a conventional manner.
• the groove 10 and the porosities of copolymer form a continuous flow between the trabecular incision and the conjunctiva without risk of obturation whatever the formation of fibrosis in the sclera.
• FIG. 9 shows a variant of an implant, the characteristics of which are identical to the previous one, except for the shape of the trabecular end referenced 2 ′ in this figure.
• This end is concave, substantially cylindrical, with a radius of curvature substantially equal to 6 mm (to within ⁇ 20%).
• the placement operation is analogous to the previous one, with the exception of the trabecular meshwork incision, which is not performed.
• the trabecular end is arranged in contact with the trabecular meshwork so as to conform to the surface thereof.
• the passage of humor from the anterior chamber takes place by filtration through the trabecular meshwork.
• Figure 10 illustrates in section the implant placed: it is essential to note that its subconjunctival part comes out of the sclera and is housed under the conjunctiva. Thus, the outer end pours the aqueous humor under the conjunctiva and forms a filtration bubble below it. This bubble serves as a witness to the effectiveness of the implant: visible through the conjunctiva, it makes it possible to verify that the flow takes place correctly.

Applications Claiming Priority (3)

Publications (2)

Family

ID=9464601

Family Applications (1)

Country Status (9)

Cited By (4)

Families Citing this family (99)

Family Cites Families (11)

• 1994
  • 1994-06-22 FR FR9407758A patent/FR2721499B1/fr not_active Expired - Fee Related
• 1995
  • 1995-06-20 US US08/750,502 patent/US5879319A/en not_active Expired - Lifetime
  • 1995-06-20 WO PCT/FR1995/000818 patent/WO1995035078A1/fr active IP Right Grant
  • 1995-06-20 ES ES95923418T patent/ES2117428T3/es not_active Expired - Lifetime
  • 1995-06-20 EP EP95923418A patent/EP0766544B1/de not_active Expired - Lifetime
  • 1995-06-20 CA CA002193369A patent/CA2193369A1/fr not_active Abandoned
  • 1995-06-20 DE DE69502497T patent/DE69502497T2/de not_active Expired - Lifetime
  • 1995-06-20 AU AU27983/95A patent/AU2798395A/en not_active Abandoned
  • 1995-06-20 AT AT95923418T patent/ATE165967T1/de active

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events